Letrozole

Letrozole (INN, trade name Femara) is an oral non-steroidal aromatase inhibitor that has been introduced for the adjuvant treatment of hormonally-responsive breast Y Estrogens are produced by the conversion of androgens through the activity of the aromatase enzyme. (In Vitro) :Letrozole (0.1-100 nM; 24-96 h) significantly inhibits growth of the MCF-7 epithelial breast cancer cells in a dose- and time-dependent manner.Letrozole (10 nM) significantly suppresses the stimulatory effects of testosterone on MCF-7 cell proliferation.Letrozole (10 nM; 24-48 h) suppresses the levels of secreted metalloproteinases (MMP‐2 and MMP‐9) in MCF-7 cells (In Vivo) :Letrozole (3-300 μg/kg; oral gavage once daily for 6 weeks) exhibits anti-tumor effects in rats.